The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines combust a mixture of air and fuel to generate torque. The fuel supplied to the engine may be liquid fuel and/or vapor fuel. Generally, liquid fuel is contained within a fuel tank. Liquid fuel is drawn from the fuel tank and provided to the engine by one or more fuel injectors.
Various factors, such as vibration and heat, may cause the liquid fuel to vaporize within the fuel tank. Vehicles include a purge system that traps fuel vapor and provides the fuel vapor to the engine for combustion. The purge system includes a vapor canister traps and stores fuel vapor from the fuel tank. The fuel vapor is purged from the canister and provided to the engine.
The purge system also includes a purge valve and a vent valve (e.g., a diurnal valve). Operation of the engine causes a vacuum (e.g., low pressure relative to barometric pressure) to form within an intake manifold of the engine. Selective actuation (i.e., opening and closing) of the purge valve and the vent valve allows the fuel vapor to be drawn from the vapor canister into the intake manifold. In this manner, fuel vapor is provided to the engine for combustion and purged from the vapor canister.